Present day methods of semiconductor symbolization to identify the semiconductor includes printing the symbolization with ink base printing machines. Several methods of printing have been used. One of the most common methods uses a solvent base, semi-liquid ink that is transferred to the molded body of an integrated circuit by means of a transfer pad which collects the ink from a reservoir, and then transfers the ink to a template with the device type identification.
The printing process requires that the surface of the encapsulated device be clean, free of oil and wax. The cleaning is usually accomplished with solvents CFCs (chlorofluorocarbons), and then heated to a specific temperature for a specific time period. After the symbolization process, the ink needs to be cured or dried. This is usually accomplished through a batch cure oven, such as a convection over, or by an ultraviolet cure process, which is required of some specially formulated ink.
The need for process simplification and an environmentally safe process provides the need for the development of new methods of device symbolization.